As wireless industry expert David Witkowski rose to present a guest at a San Jose conference, he pocketed his phone in defeat.

Unable to call up the speaker’s resume — network coverage and WiFi had failed during the conference about Silicon Valley network reliability — Witkowski winged an introduction.

“I’m being hoisted by my own petard,” he told the crowd of business leaders. “I wasn’t able to get a data connection.”

It’s a cry heard around the Bay Area.

Silicon Valley, capital of high-tech and hub of innovation,is stalled in a wireless traffic jam of its own making. Increasing demand for data — driven by the products made by Bay Area tech companies – and lagging infrastructure coupled with intense local politics have helped create the dropped calls, frozen videos and blank web pages on our screens.

Industry analytics company RootMetrics ranks San Jose at 49 and San Francisco at 58 out of 125 metropolitan areas in quality of mobile network service. That puts the Bay Area ahead of Santa Rosa (122) but lagging far behind Modesto and Sacramento (7 and 8).

Without a better network, the ripple effects could swamp next-generation products — autonomous vehicles, energy-efficient smart cities and the vast universe of the Internet of Things.

“We worry about how good is the coverage and how fast is the coverage,” said Jon Walton, co-chair of a Joint Venture Silicon Valley task force on wireless network coverage, organized by Witkowski. “You can’t let your infrastructure degrade.”

But getting better cell coverage in Silicon Valley is complicated. It’s a messy, block-by-block battle in city after city with shifting alliances. The fights pit community activists, wireless companies, government planners and consumers against each other.

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It doesn’t help that the Bay Area has a challenging geography for sending crisp signals. For starters, the Bay can muddle signals. The hills and redwoods collude to block transmissionsthat require line-of-site to properly connect.

But even more challenging are local politics.

A complex mix of aesthetics and environmental fears often hamstrings new antenna projects. Communities are willing to wage guerrilla warfare against cell phone towers, worrying they will ruin their health ortheir view.

Regulators and network engineers insist the radiation levels emitted from towers are safe, and at lower levels than simply using a smartphone. Since local governments can’t reject a structure because of the power it emits, local battles rise up where cities and municipal agencies have control — site location and aesthetics.

Consider the recent rancor in local courts and public meetings across Silicon Valley.

Cupertino residents last year protested a proposed 80-foot tower at the civic center — thinly disguised as a cluster of eucalyptus trees — about a mile from the Apple Campus at One Infinite Loop. Dan Allen, a local resident opposed to the tower, said he is concerned the tower is being built too close to homes and government offices. He also feels the city could cut a better deal with the wireless company for using public property.

Allen knows there are occasional dead spots in cell coverage. But, he said, “Do you really want a cell tower at the entrance to city hall?”

The City Council did. A slightly shorter tower was approved and built.

Sometimes, the battles go on for years. In 2010, Verizon proposed extending a light post 5 feet to host an antenna on the Palo Alto Little League field.

A group of neighbors rallied to stop the antenna. But more than 250 other residents testified and sent texts and emails to the city to complain about the area’s miserable service. Some said they stood outside in the rain — umbrella in one hand, phone in the other — to get better reception. Another failed to connect to 911 during emergencies.

A Stanford nurse e-mailed the city to support the new tower in her neighborhood.

“I have cared for patients whose lives were saved by the use of cell phones,” she wrote. “Palo Alto, in the heart of Silicon Valley, should be embarrassed that we have such poor service at this end of town. We live in the shadow of Stanford; shouldn’t we have state-of-the-art communications capability?”

Sullivan, who lives in an eco-friendly home in Los Altos, believes exposure to certain radiation and poorly engineered electrical systems can cause health problems ranging from insomnia to autism. Sullivan said his own family has suffered from its effects.

“I love technology,” he said. “I want it to be safe.”

In the end, the proponents for better service won out. The tower was built in July, six years after Verizon’s initial proposal.

Commuters and longtime residents know about the hassles of inconsistent mobile service. Jim Wissick, a 45-year-old driving instructor from San Jose, said he switched carriers after encountering so many dead spots.

Network coverage isn’t just a convenience — it’s vital infrastructure. About half of all Americans have abandoned landlines for cell-only connections. A White House study found that unemployed workers are more likely to get back into the workforce, and faster, when they have internet access.

The amount of mobile data consumed worldwide is expected to increase eight-fold by 2020, according to a forecast by Cisco. “The curve is exponential,” Witkowski said, “and we’re not slowing down at any point.”

Planners and entrepreneurs say the stakes are high for the region’s own dominance.

Smart buildings and cities – using networks to increase energy efficiency and move traffic faster – will be competing for bandwidth with connected vehicles, appliances and other new products.

Engineers say the technological challenges can be met across the region with a combination of towers, small-cell transmitters and new innovations. It could mean more low-powered antennas scattered throughout neighborhoods.

Planners say cities need to take a regional approach to building networks — and also urge carriers to improve service in rich and poor communities.

Walton suggests local and regional governments develop master infrastructure plans with community input. Does Silicon Valley want lightning-fast connections like Seoul, South Korea, with visible antennas as common as street lamps? Or are residents content with fewer towers and spotty service?